1. Field of the Invention
The present invention relates to a perpendicular magnetic write head and to a magnetic recording device mounted with the same.
2. Description of Related Art
In recent years, along with an increased surface recording density in a magnetic recording medium (hereinafter, referred to as a “recording medium”) typified by a hard disk, as a recording system of a magnetic write head, a perpendicular magnetic recording system in which a direction of signal magnetic field is set to a direction intersecting a surface of a recording medium is now the mainstream. This is because advantages that a track recording density is high compared with an existing longitudinal magnetic recording system and a recording medium in which information has been recorded is less likely to be affected by thermal fluctuation, are obtainable.
A magnetic write head in the perpendicular magnetic recording system (hereinafter, referred to as a “perpendicular magnetic write head”) includes a main magnetic pole that guides magnetic flux generated in a thin film coil to a recording medium. The main magnetic pole includes a front end section (a magnetic pole) with a slightly small width. The front end section (the magnetic pole) of the main magnetic pole emits magnetic flux to generate magnetic field for recording (perpendicular magnetic field).
Most recently, there is a tendency that demand of improvement in the surface recording density of the magnetic recording medium is further increased. In such a circumstance, to obtain recording property of the perpendicular magnetic write head stably, for example, it is necessary to suppress wide adjacent track erase (WATE) effective magnetic field as much as possible. If the WATE effective magnetic field is not suppressed sufficiently, information recorded in tracks adjacent to a track to be written may be unintentionally overwritten with wrong information. The WATE effective magnetic field means effective magnetic field affecting adjacent tracks within a wide range (for example, two to ten tracks adjacent to a track to be written), out of recording magnetic field emitted from an air bearing surface toward the magnetic recording medium.
On the other hand, to address an increase in the surface recording density of the magnetic recording medium, improvement in high frequency property of the perpendicular magnetic write head is demanded.
However, in the existing perpendicular magnetic write head, shape of each of first and second yokes influences both the high frequency property and the WATE effective magnetic field. Here, a tradeoff relationship is established between improvement of the high frequency property and reduction of the WATE effective magnetic field, and thus it is difficult to achieve both demands.
Against this background, it is desirable to provide a perpendicular magnetic write head and a magnetic recording device that are capable of reducing the WATE effective magnetic field while ensuring favorable high frequency property, and thus addressing higher density recording.